Fungal detoxication. The metabolism of ω-(2-naphthyloxy)-n-alkylcarboxylic acids by Aspergillus niger

Abstract
By means of a replacement-culture technique 2-naphthyloxyacetic and [beta]-(2-naphthyloxy) propionic acids were hydroxylated in the 6-position by Aspergillus niger. 7-(2-naphthyloxy)-n-butyric acid, was similarly converted into [gamma]-(6-hydroxy-2-naphthyloxy)-n-butyric acid, which was subsequently [beta]-oxidized to (6-hydroxy-2-naphthyloxy) acetic acid. Higher members of the [omega]-(2-naphthyloxy)-n-alkylcarboxylic acid series (C10H7.O. (CH2)n-CO2H, where n=4-9), likewise underwent hydroxylation and [gamma]-oxidation. There was no evidence to suggest why [gamma]-(6-hydroxy-2-naphthyloxy) propionic acid did not undergo [beta]-oxidation. Hydroxylation of the acetic and propionic acids led to a decrease in toxicity to the fungus.